In today's domestic water resource recovery facilities (WRRFs) and wastewater treatment plants, vortex grit chamber systems dominate the landscape and for good reason: they capably protect downstream processes and equipment from abrasion or poor performance from reduced capacity. Forced hydraulic vortex systems, such as the Smith & Loveless (S&L) PISTA® Grit Removal System, are commonly specified not only because of grit removal efficiencies but also decades of product performance and system development over time.
Forced hydraulic systems aren't settling devices like most other grit systems; instead, the chamber geometry regulates and optimizes flow velocities to generate a true forced hydraulic vortex path that effectively removes grit. To accomplish this hydraulic action, the systems combine a specifically inclined inlet flume; a circular chamber with a flat-floor upper chamber and a lower collection hopper; an effluent trough that emanates 270 or 360 degrees from the inlet; and, depending on the design flows, patented integral baffle arrangements.
Recent S&L developments in forced vortex chamber technology provide for the finest of grit removal and the industry-standard 95 percent removal efficiency for grit particles sized down to 105 microns (140 mesh). The driving force, literally, is the integral V-FORCE BAFFLE™, which ensures the proper velocity and extended flow path around the entire 360 degrees to sweep the entering grit along the chamber flat floor and into a center core opening to the lower collection hopper.
The nearby center rotating paddles above the opening serve to lift and separate lighter organic material in the center (enabling it to continue downstream), while the heavier grit particles retreat to the lower hopper. No additional downstream control devices are required to keep the velocity in the preferred range during both peak flow and minimum flow, as the system possesses a 10:1 turndown.
Now, at WEFTEC 2015, S&L is introducing two new integrated baffle and forced vortex technologies -- the PISTA® Vio™ and OPTIFLOW 270™ Baffle System -- that address varied needs for WRRFs. The PISTA Vio offers the flexibility of the inlet and outlet channels at any variable angle up to the full 360 degrees of the circular chamber, offering simple installation into existing sites or an efficient footprint for new sites. A hydraulically forced ring and tunnel system still creates the vortex flow path necessary to provide 95 percent grit removal down to 105 microns while allowing additional layouts beyond the typical 360- or 270-degree arrangements.
The new OPTIFLOW 270 Baffle System addresses the numerous 270-degree vortex grit chambers that were installed throughout North America and elsewhere in previous generations. The technology can be retrofitted into those systems in order to augment removal efficiency. With the retrofit, vortex grit removal systems designed to meet previous standards can be upgraded to remove 95 percent of grit down to 150 microns (100 mesh). This baffle is available not only for flat-floor vortex chambers but as a conversion system for sloped and cone-shaped chambers. Likewise, it can be installed for new systems requiring 270-degree layouts.
Smith & Loveless is an exhibitor at WEFTEC.15 and can be found at Booth 3648. For more information, visit www.smithandloveless.com.
